Who needs theatre designers? If you were to read some of the comments in response to Matt Trueman's recent blog about fringe theatre, you might be forgiven for thinking that the way a show looks is entirely incidental to its success. Trueman made the point that, often, tight budgets on the fringe mean "props and furnishings stand in not for their fictional counterparts, but rather for the props and furnishings that would have been bought had the funds been available".

Yet this quite reasonable, accurate observation seems to have offended those of his readers who think good design is an unnecessary luxury. Joyandtears asks: "Who cares about the chronological accuracy of costumes or props?"; naimakhan adds that "dodgy sets and costumes are easily forgiven when presented alongside a poignant, evocative script and compelling characters"; MaxCairnduff suggests that "props are not the point"; while ABtheatre dismisses Trueman's comment as "a joke".

It's true that a tight budget can prevent a show from having a complex set or a vast array of props. But it doesn't prevent a company from using its imagination and being creative with what it has. In fact, if you have no design budget, that's all the more reason to get a designer on board. Having someone who can think visually, who can work within tight constraints but still be creative, and who is able to beg, borrow or steal for the show is vital.

If all a theatre company can afford is a single chair on an empty stage, then fine. But that still begs a number of questions. What kind of chair? Does it have armrests? Is it padded? Is it made of plastic or wood? And, for that matter, what kind of empty stage? Is it freshly painted, or worn and old? Given that these are the main things – other than the actors – that an audience will look at for the duration of a show, the answers to these questions are vital. We no longer live in Shakespeare's time, when people went to the theatre to "hear" a play; these days we go to see a show.

Good design is not a luxury only afforded by those in receipt of a nice big Arts Council grant, it's an essential part of any production. Sure, a well-chosen prop is no substitute for good acting, but then, good acting is no substitute for a well-chosen prop. Of course, great performers can shine despite a crappy set. But they are still going to have to work that little bit harder to stop the audience from noticing that the Russian nobleman they are portraying is sitting on a plastic chair borrowed from the theatre bar. And if a play really makes aesthetic demands that are impossible to achieve on a shoestring budget, then maybe it's not the right play to take to the fringe in the first place. Detail matters. And while a limited budget might excuse a simple design, it is never an excuse for a bad one.